That depends on what you would call "famous." Really, Coldplay has always been pretty well-known. "Yellow" made them famous in 2000/2001. "Clocks" made them even more famous in 2003. "Viva la Vida" made them REALLY famous in 2008.
The two songs that have recently made them really famous are Uprising, and Supermassive Black Hole.
Robert Schumann
Leonard Cohen
The song that first made the Troggs famous was Wild Thing. Other famous songs recorded by the Troggs include Love is All Around and With a Girl Like You.
"Plethora" is a singular noun, so you say "is a plethora."
Matt Hasselbeck is famous for a plethora of reasons. The most commonly recognized reason that he is famous is because he is the quarterback for the Colts American football team.
Plethora is singular and the plural form is plethoras
(Plethora means an abundant excess as a bountiful excesss such as riches.)"The Thanksgiving feast was a plethora of favorite foods of the family.""There was a plethora of costumes to choose from for the masquerade.""From the plethora of possible names for the project, he chose the most apt."
"Is", since plethora is in singular form
There was a plethora of food on the table at Thanksgiving.
Plethora is a noun.
The noun plethora (a plethora) uses singular verb forms.The word plethora is an uncountable (mass) noun, a type of aggregate noun that refers to an unspecified but large number of elements, e.g. a plethora of choices.
Plethora is singular and the plural form is plethoras.
The plethora of escapes from supposedly secure prisons embarrassed the hapless wardens. The success of his videos inspired a plethora of imitators.
"There was a plethora of items in her desk." "Plethora" is not a verb / action word, so it will not change forms from a present to a past tense.
superabundance, an excess